/*
 * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.svm.hosted.webimage.codegen.type;

import com.oracle.svm.hosted.meta.HostedMethod;
import com.oracle.svm.hosted.meta.HostedType;
import com.oracle.svm.hosted.webimage.codegen.JSCodeGenTool;
import com.oracle.svm.hosted.webimage.js.JSKeyword;
import com.oracle.svm.webimage.hightiercodegen.CodeBuffer;
import com.oracle.svm.webimage.hightiercodegen.Emitter;

public class TypeVtableLowerer {

    private final HostedType type;

    public TypeVtableLowerer(HostedType type) {
        this.type = type;
    }

    public static final String VTAB_PROP = "vt";

    /**
     * Extend the static hub of a prototype via the vtable.
     */
    public void lowerInitialDefinition(JSCodeGenTool jsLTools) {
        if (type.getVTable().length == 0) {
            return;
        }

        HostedMethod[] vtable = type.getVTable();
        CodeBuffer masm = jsLTools.getCodeBuffer();
        String vtableAccessName = jsLTools.getJSProviders().typeControl().requestTypeName(type) + "." + VTAB_PROP;
        jsLTools.genResolvedVarAssignmentPrefix(vtableAccessName);
        masm.emitKeyword(JSKeyword.LBRACK);

        for (HostedMethod hm : vtable) {
            if (hm != null) {
                masm.emitNewLine();
                jsLTools.genPrototypePropertyAccess(Emitter.of(hm.getDeclaringClass()), Emitter.of(hm));
            }
            /*
             * For empty elements we can just not emit anything [foo,,bar] gives a three element
             * array with an empty element in the middle
             */
            masm.emitText(",");
        }
        masm.emitNewLine();

        masm.emitKeyword(JSKeyword.RBRACK);
        masm.emitInsEnd();
    }
}
